Furnace



June 9, 1925.

J. D. MARTIN FURNACE Filed Nov.'12. 1925 4 sheets-sheet 1 m, w ...mf/m M um A D ,U nrlJ .w Y Tm B June 9, 1925.

J. D. MARTIN FURNACE Filed Nov. 12, 1923 4 Sheets-Sheet 3 l//ll//r/l/l/ .//f/

Inventor,

John D. Martin,

Attorney June 9, 1925.

J. D. MARTIN FURNACE Filed Nov. 12, 1923 4 Sheets-Shet 4.

Inventor, 1

john D. Martn, B 77//.

At tol" may.

Patented June 9 192,?5..

UNITED STATES PATENT orifice.

JOHN D. maar, or Naw s'mArrsvILLE, omo.,

FURNACE. a

To all whom tmay concern: v i Be it known that I, JOHN D. MARTIN, a

citizen of the United States of America, and. a resident of New Straitsville, Perry County, State rof Ohio, have`invented certain new and useful Improvements in Furnaces, of which the followingis a speciiication. This invention relatesto coal-burning fur.-

naces, and particularly to furnaces of a circular grate type with automatic means for introducing the fuel from underneath and for removing the ash and siftings.

. 011e object of this invention is to provide a' construction in which 'the .mechanical parts are safeguarded against eXtreme heat. Further-,objects are to provide for proper distribution'of fuel over the grate and to prevent disarrangement of the mechanical action ,or stoppage through fusion of slag to the furnace walls or warping of the grate rings or wear' of the parts.

In the accompanying four sheets of drawings which form apart ofthis` speciication,

Figure 1 is a vertical section through aI furnace embodying this invention ori the line I-I of Fig. 2;

Fig. 2 is a horizontal section through the furnace on the line II-II of Fig. 1; p

Fig. 3 is a vertical section drawn to a largerscale showing the portion within the furnace, the grate and the conveyor tube also being shown in'section; and

Fig.'4 is a plan of the portion of the apparatus' within the furnace, showing the ash-ring and omitting the grate rings.

' This invention is illustrated in connection with a brick-kiln in which a number of furfnace units are each built partly in the enclosing wall of the kiln.

For each unit a semi-circular niche is made in the inner side ofthe wall 10 and the circle is completed by a semi-circular wall 11 whiclr is carriedsto a height of about five feet. The semi-circular walls are not bonded to the furnace wall and are independentlyrenewable. There is a lower opening through the, kiln wall through which theconveying apparatus passes and there is an upper opening closed by a furnace door throughl which the condition of the fuel bedV can be inspected. ,The lower opening is bricked up around the apparatus so that the entrance of air for combustion may be better controlled. A ledge 12 Application led November 12,' 1923. Serial N10. 674,176.) v

in theV furnace Wall supports a frame 13. Curved arms 14, 14 extend. inwardl from this ring to-a central hub 15 to whic a two-chambered casting 16 is bolted.` A. `vertical fuel-conveyor tube 17 is screwed into an opening in the toplwall of this castnor ing and a horizontal fuel-conveyor tube 18 l is screwed into a side wall'of the same chamber of the casting, and-extends through the wall lof the kiln to a point outside the furnace. J-It is customary to rivet light longitudinal strips to keep the coal from turning with the screwsf An ash-ring 19, as large as or slightly larger in outside diameter 20`extending inwar to al central hub 21 which is carried bythe vertical conveyor tube which serves as an axle therefor. Slots in the side of the hub let out any coal siftings which may get into the bearing.

YBy reason of the arms of the ash-ring and ofthe supporting ring being curved they will not be unduly strained with the eX- pansion or warping of the rings by the heat of theV furnace which will be more direct on the rings than on the arms. As the ashbring it into contact with anything to limpede its movement and vthere is always a free passage for air around it to keep it from being unduly heated. The top of the than the frame ring, has curved arms 20, 1y

ring is supported through its hub and -not at its rim, expansion or warping will not ash-ring is'inclined about eight degrees andA below the top of the central hub and the falling of siftings in quantity between the ring and the hub is thereby prevented.l Three legs or pins 24, 24 on the underside They overlap v i of each ring support it from the ring underneath and leave a Ahorizontal passage for air. This three-point support avoids any instability -arising through the warping of the rin s.` Three longer pins 25, 25 center each .ring from the one underneath. As

the grate rings are supported whollyl from` i and insure that the `fuel will be carried the `ash-ring they will revolve with it. On the upper side of the lowerinost grate rings are lugs 26, 26 which engage the bed of fuel around with the grate. rilhere are air-holes through these lugs to keep them from burning off. lln the vertical fuel-conveyor tube is a vertical helical fuel-conveyor 2T. 'l'his rests on a partition wall 28 in the two-chambered casting which takes the weight and thrust.' A sleeve 29 ytapped into the partition wall yand support-ed thereby projects upwardly into a `hole in the lower end of the vertical kconveyor and serves as a guideV rfhs sleeve prevents fine coal Vfrom working through the bearing into the therefor.

lower chamber. Above the end of the sleeve the hole in the vertical conveyor is square, and a shaft 30 passes through the sleeve and has a scpuare upper end 31 which engages the square part of the hole in the conveyor. rfhe shaft 30 should `be hollow to provide at its top for lubricating the joints between `the sleeve and the shaft and the shaft and the sleeve and the conveyor. fn the lower chamber are two bevel gears in whichthefollowing gear 32 is attached to the vertical shaft and the driving gear 33 is on the end of a horizontal shaft 34. rfhe square end of the verticalshaft does not bottom in the hole in the conveyor so that settling of the conveyor with Wear will bring no ond pressure ont/the shaft which would tend to'throw the bevel gears out of proper mesh. l.,

f Siftings will accumulate in the pit around the two-chambered casting, buton the front side they Will not accumulate above the horizontal shaft for'this is provided with an' ash-conveyor helix 35 which willtake ashes away from the mouth and Will draw the siftings out of the pit on the front side down to its level.- lin other parts of the pit the slftings cannot accumulate higher thanl Scrapers' 36, 36 which are carried around with the revolving grate and ash-ring and carry out further accumulation of siftings around to the front side over the "aslbconveyor.v ,ffhere will therefore be an air space preserved ab'ove the Scrapers and under the grate which is clear of siftings. Air isA forced into this space through an opening 37 l `est in the framering. The air flow is in the direction in which the grate and the vscrapels rotate and "assists the Scrapers in carrying the siftings around to the front side'and feeding them tothe ash-conveyor. lThe air` is forced between the grate rings and through the fuel bed. There is also some vescape of air around the outer edge of the ash-ring through which secondary air is supplied' above the fuel bed for completing the combustion of unconsumed gases arising from the"bed. In practice the -forced draft` ywill be adjusted slightly in excess of the pull of the stack `"so that there will be 'a Ysecon-(lary air from the forced draft.

.power to the vertical fuel conveyor.

1 intensas slight tendency of the burning gases to bloxv wall it will be heated thereby to combustion temperature before coming into contact with the combustible gases from vthe fuel bed. 'fhis airalso slightly cools the furnace wall where fused ash might be likely to touch it and prevent the ash from forming adher ing clinkers.

A revolving ash-scraper 38 removes the ashes from the ash-ring. YIt has a more positive action than a fixed scraper, no one arm is inthe fire long enough to be injured by the heat and besides it is cooled by the 'i`he ashesas scraped off fall to the mouth of the pit. AThey are in part carried out therefrom by the ash-conveyor toja point where they are easily reached for: removal with a shovel. Power for continuous operation of the moving parts issupplied from a shaft 40 in sections surrounding the kiln and con nected by universal joints 41 41. Power is transferred from each section to the` adjacent furnace apparatus through a pair of bevel gears, one of which 42 is on the driv ing shaft and the other of Which 43 is attached to the end of the shaft of a horizontal helical fuel-conveyor 44 which leads from the hopper 45 to thebaseof the verticai fuel conveyor. ,'fhe gear on the power shaft is driven through a pair of dogs 46, 46 one of which is attached to the shaft and the other of which is attached to the gear. These, dogs are connected by a wooden pin 46 so.

that in. case-the conveyorsy of any furnace should become blocked, connection will glve replaceable is avoided.

A pair of spur gears, one of which 47 is attached tothe shaft of thehorizontal helical conveyor, and the other of Which 48 is the smaller ofthe two and is attached to the shaft of the ash-conveyor, transmlis `s the gears are of unequal size the vertical fuel -conveyor will be driven faster than the horizontal fuel conveyor and the'l vertical. fuel conveyor will be certain to take away all of the fuel delivered to it by the'horizontal fuel conveyor so that choking at the point of transfer Will be avoided Without making the vertical conveyor. pipe .larger and encroaching on the eective grate area.

A Worm 50 on the shaft ofthe helical ashconveyor drives a Worm-Wheel 51. The worm-'Wheel drives a pin disk 52v in conjunction With which is a second pin disk 53.

-junction with others.

A pin of one disk is connected to a pinof the other disk by an easily fractured link 54. which will break before other parts in case the grate or ash-ring or scraper should be blocked. One vpindisk preferably has one more pin around its circumference than the other. In consequence, should it be necessaryy to replace a link, but a small part of a revolution will ever need to take place before two pins will be in proper relation to receive a new link. The second pin disk connects to a sprocket 55 from which a chain 56 connects to the sprocket which revolves the ash-ring and the grate. One run of the chain engages a sprocket 57 which is attached to the revolving ash-scraper.

The apparatus proportioned' as shown is suitable for a furnace about forty inches in diameter but the invention is applicable to furnaces larger or smaller than this and which are operated singly as well as in con- The apparatus is driven so that the horizontal fuel conveyor will make about four revolutions a minute'. A good ratio between the horizontal and the vertical fuel conveyors will make about twenty to twenty-eight revolutions. The ash-ring and grate will require about fifteen minutes for a revolution. 'Adherence to these speeds, however, is' not essential to the invention. The vertical conveyor re lvolves more rapidly than is necessary for the feeding of fuel, 'as one of its other functions v is. to stir up the fuel bed at the apex of the Ythe different slopes.

cone to insure a more even distribution on I claim- .Y

1. In a furnace,'a conical grate, an under-` lying ash-ring, a scraper with radiating arms for removing ashes from the ash-ring, and means for revolving the ash-ring and the scraper.

2. In a furnace, a conical grate, an underc lying ash-ring, a scraper for removing ashes from the ash-ring, ahelical conveyor underlying the scraper for conveying the ashes. and means for revolving the ash-ring and the conveyor. f

BjIn a fnrnace,'a conical grate, an under lying ash-ring,4 a vertical helical fuelconveyor. a bevel-gear transmission underlying the fuel-conveyor, a scraper for removing ashes from the ash-ring, and-a horizontal helical ash-conveyorv which underlies the scraper and through which power is communicated to the bevel-gear transmission.

l. In a furnace, a conical grate, an under# lying ash-ring, a vertical helical fuel-con veyor. `a bevel-gear transmission underlying the fuel-conveyor, a scraper for removing ashes from the ash-ring, 'a horizontal helical ash-conveyor which underlies the scraper A through which power is communicated to the bevel-gear transmission, and means for revolving the ash-ring and the conveyors.

5. In a furnace, a conical grate, a horizontal helical fuel conveyor, a vertical heli cal fuel conveyor through the center of the grate of as small diameter asthe horizontal conveyor and receiving fuel therefrom, and means for driving the vertical conveyor more rapidly than the horizontal conveyor.v

such in connection with the bevel gear transmission that the vertical fuel-conveyor will be driven more rapidly than the horizontal fuel-conveyor.

JOHN D. MARTIN. 

